I love how reporters use the word: 'vow'.
It's like; what's that? Ohh, you mean a promise or an assurement? This isn't The Marvel Universe.
NK waits for Winter to wane, then basically sabre-rattles the rest of the year. That's their MO. SK has a lovely assortment of Hyunmoo 3 cruise-missiles aimed at the North, who can't even launch a missile correctly. The kids-at-the-end-of-my-street forgot more about rocket-technology than NK will ever dream of acquiring.